Abstract:The eco-environment rehabilitation project is the first ba ttle for Shaanxi province to carry out a great dev elopment in the west of China. With a detail investigation, some new valuable experience are summerized that to turn deep slope cropland into grassland or forest land should be under taken in a comprehensive management, benefits both from forestry and animal husbandry obtained, erosion control promoted by using a market system and revegetation speeded up on natural regenerative ability. Meanwhile, the major existing problems are discussed and some important suggestion proposed for making policies to acceler ate the im plementation of the project.

Abstract:It is a great significance for dike to ensure the safety of flood control, the people's life and properties. The main forms and harmfulness of dike erosion in the lower and middle reaches of Chang jiang river are summarized. Combining the danger-control practice of dike building, the relevant principles and technical measures for the prevention and cure of dike erosion are put forward.

Abstract:The saturated hydraulic conductiv it ies of mainly paddy soil in Taihu lake region were studied. The results were as follows. (1) The saturated hydraulic conductivities in the soil were changeable from 7.20×10^-5 to 6. 33×10^-4 cm/ s and decreased with the increasing of soil depth.(2) The saturated hydraulic conductiv it ies of undistur bed soil and distur bed soil were quite different and affected by soil texture, organic matter content, bulk density, porosity and structural index. The saturated hydraulic conductivity of undisturbed soil can represent the really case in the field and is significant to study soil moisture balance and soil water conservation. But the saturated hydraulic conductivity of disturbed soil can only be used for a reference information in agricultural engineering.

Abstract:The water chemical elements of Robinia pseud oacacia water protect ion forest in the Miyun reservoir watershed are studied. The results show that the precipitation contained the total chemical elements amount was 12.00 mg/Lin the mainly rainfall period, the highly sample arisen in the June. The consequence of water chemical elements contained as follows: Ca>N> K>Mg>Na>P>Fe>Zn>Cu>Mn. The chemical elements that throug h-fall and stem-flow contained was varied in different direction, but as the sumup of the variance quantity that the total contained amounts were increased as comparison with that of the precipitation. The total chemical elements contained of thr ough-fall, stem-flow was 46.192 m g/ L and 61.586mg/L, respectively, it is 34.191 mg/L and 49.585 mg/L higher than that of prcipitation, respectively.

Abstract:Based on analysis of soil erodible factors, some information about soil erosion in the limestone mountain area were gained. Then the surface run off equation with variable parameters and the Universal Soil Loss Equation were used to compute and predict the volume and the rate of run off and soil loss in the different period of building project. Finally, the soil loss properties in limesto ne mountain area affected by the artificial engineering are summarized.

Abstract:According to detailed data that are gained by 7-year tests of the different cultivation of the slope land in the loess hilly and gully region of the north of Shaanxi province, water use of the different cultivation, water balance, outputs and comprehensive efficiency of soil and water conservation are discussed. The conclusion is that crop grow this mainly dependent on natural rainfall during the growth period; water-consuming content of crop is significantly relative to the rainfall during the growth period per year and water supply content of soil, and crop makes mainly use of soil moisture of 0-120cm layer. The comprehensive efficiency sequence of the different farming sat the same year is broadter race> narrow ter race> level trench >traditional tillae> level bench> alternation of slope and terrace, while the soil and water conservation efficiency sequence is terrace> level trench> alternation of slope and terrace> level bench> traditional tillage>bare land. Finally we think that quitcultivating and resto ring and rebuilding forest and grass should be quickly put into practice in order to accelerate the ecoenvironmental constr uction, and strategic adjustment of agricultural structure should be advanced.

Abstract:The satellite remote sensing technology, the method of the surface run off collection of erosion plot and the evaluation method of agricultural eco-economy are used to investigate the soil erosion, the situation of land use, the storage volume of soil and water conservation woods, the coverage of forest and grass, the increasing output of grain, the storage volume of closure-preserved forest and young growth in restored Longchuan small watershed, Muding county, Yunnan province, which has been harnessed for 8 years. It indicates that after five-year harness and preservation, the soil erosion amount decreases from 594.00t of 1989 to 177.00 t of 1997, as occupies 29. 7% of the 1989s erosion amount. Among the types of land use, the square of dry land decreases 499.40hm²;the one of terrace increases 517hm²; the square of man-made woods increases 9484 hm². The storage amount of soil and water conservation woods is 223460m³ per year and that of closure preserved forest and young grow this 53171 m³. The coverage of forest and grass goes up to 74.6% of 1997 from 38. 95% of 1989; the total amount of grain is 2.89× 10⁷ kg, increased by 34.3%; the amount of agricultural productis 4935kg /hm²; the pure income of a farmer is 511 yuan.

Abstract:Based on the monitor of sediment and water in Tiaozi river in Siping city from 1987 to 1995, some characteristics of heavy metals in the sediment are pointed out. The content of heavy metals in the sediment was high and it in the polluted sediment was 1～ 3.97 times of that of the backg round, the annual variation was undulant. The content of heavy metals in the sediment is affected by the acidification or alkali and oxidation of water, the regional background and the drainage of industry waste water. At last, some ecological and chemical countermeasures to control the heavy metal in sediment are given out.

Abstract:The hydro-ecolo gical ef fects of the every layer of forest and its soil and water conservation benefits in the loess plateau are generally expounded. On the basis of these, the suitable index of vegetation coverage for protecting ecological environment and coordinating economy development is advanced in conformity with the natural conditions, landforms and the demands of national economy development.

Abstract:The gully density, constructed damdensity, and the ratio of damland to arable and land in the seven towns of Baota district and Ansai county in south Yanan city are analyzed. The pattern of constructing dam system and the constructing scale of damland in the region are put forward.

Abstract:The basic assuming of the dynamic monitor system on soil and water loss in the west of China is put forward. The content model of monitor and technic program are introduced. The feasibility of implementing all-in-all monitor on remote-sensing image and ground image with the integrate apply of BPAN NS technique and wavelet image switch over technology are probed into.

Abstract:The necessities and feasibilities of undergoing water-saving irrigation in Shaanxi province are analyzed, and the developing patterns and prospect of waters-saving irrigation in different parts of the province are inquired into. It offers measures that later after constructing projects, attention should be given to the well planning first; then based on the principle of easy plans first, difficult ones afterwards, those plans should be made fulfilled, and that the steps of popularizing the technologies of water-saving irrigation of stored rainwater should be quickened, that projects management should be enforced and scientific studies should be emphasized more.

Abstract:The effects of different water-retention treatments such as covering with veil, covering with grass and using water-retention preparation are studied. The conclusion obtained is as follows: the SWC was significantly increased by using water-retention preparation; the sequence o f water-retention ef fect in three kinds of land was old terraced field> slope field> new terraced field; the sequence of water-retention effect was covering with veil> covering with grass> check.

Abstract:According to the basic features in loess hilly region, the basic concept of landscape cell and its distributed law are described, the technological approach of digital landscape cell is explored. As an example at Yan gully watershed, the procedure, the approach and the importance of digitallandscape cell in ecological agriculture constructing are primarily discussed.

Abstract:Based on the analysis of deserti fication states and its dynamic monitoring results, the contributing factors, types a nd dev elo ping utiliza tions of desertification in Yunnan province are discussed, and the corresponding prevention countermeasures are presented.

Abstract:Some problems, such as irregular structural measure, low cover degree, lowutilization ratio of light and poor soil fertility, existed in the eroded slope lands which were used as orchard, can be resolved through ripetech nology present. However, the advanced management measures on the slope orchard could not be popularized, because the farmers did not have high technical level and they were not aware of soil and water conversation and ecological cultivation on orchard. Therefore, some measures can be arranged to assure maintainable utili zation of eroded slope orchard, which strengthen propaganda for spreading science and technology, improve the farmer's and even the public 's consciousness of soil and water conservation,reform the conventional concept of cultivating and managing the orchard, spread the mode of ecological cultivation in orchard,e.g.,grass mulching.

Abstract:The notable effects of dams to soil and water conservation and the sand decrease of coming into the Yellow river in Hongliu river basin in north Shaanxi province are analyzed. It is emphasized that engineering measure is very important in the course of controlling soil and water loss. According to the dams existing circumstance, some serious issue with these dams is pointed out. It is considered that these dams should be reconstructed and fastened as quickly as possible.